38a54df863
People keep tripping over the old copyrights and copy-pasting them to new files. Search and replace "Cloudius Systems" with "ScyllaDB". Message-Id: <1460013664-25966-1-git-send-email-penberg@scylladb.com>
83 lines
2.3 KiB
C++
83 lines
2.3 KiB
C++
/*
|
|
* Copyright (C) 2014 ScyllaDB
|
|
*/
|
|
|
|
/*
|
|
* This file is part of Scylla.
|
|
*
|
|
* Scylla is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU Affero General Public License as published by
|
|
* the Free Software Foundation, either version 3 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* Scylla is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with Scylla. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
|
|
#include <core/reactor.hh>
|
|
#include <core/posix.hh>
|
|
#include <unistd.h>
|
|
#include <fcntl.h>
|
|
|
|
#include "file_lock.hh"
|
|
|
|
class utils::file_lock::impl {
|
|
public:
|
|
impl(sstring path)
|
|
: _path(std::move(path)), _fd(
|
|
file_desc::open(_path, O_RDWR | O_CREAT | O_CLOEXEC,
|
|
S_IRWXU)) {
|
|
if (::lockf(_fd.get(), F_TLOCK, 0) != 0) {
|
|
throw std::system_error(errno, std::system_category(), "Could not acquire lock: " + _path);
|
|
}
|
|
}
|
|
impl(impl&&) = default;
|
|
~impl() {
|
|
if (!_path.empty()) {
|
|
::unlink(_path.c_str());
|
|
}
|
|
assert(_fd.get() != -1);
|
|
auto r = ::lockf(_fd.get(), F_ULOCK, 0);
|
|
assert(r == 0);
|
|
}
|
|
sstring
|
|
_path;
|
|
file_desc
|
|
_fd;
|
|
};
|
|
|
|
utils::file_lock::file_lock(sstring path)
|
|
: _impl(std::make_unique<impl>(std::move(path)))
|
|
{}
|
|
|
|
utils::file_lock::file_lock(file_lock&& f) noexcept
|
|
: _impl(std::move(f._impl))
|
|
{}
|
|
|
|
utils::file_lock::~file_lock()
|
|
{}
|
|
|
|
sstring utils::file_lock::path() const {
|
|
return _impl ? _impl->_path : "";
|
|
}
|
|
|
|
future<utils::file_lock> utils::file_lock::acquire(sstring path) {
|
|
// meh. not really any future stuff here. but pretend, for the
|
|
// day when a future version of lock etc is added.
|
|
try {
|
|
return make_ready_future<file_lock>(file_lock(path));
|
|
} catch (...) {
|
|
return make_exception_future<utils::file_lock>(std::current_exception());
|
|
}
|
|
}
|
|
|
|
std::ostream& utils::operator<<(std::ostream& out, const file_lock& f) {
|
|
return out << "file lock '" << f.path() << "'";
|
|
}
|